Supplemental resistance for serially-mounted lamps



No'v. zo,1 192s. 1,692,272.-

A. LAMPL SUPPLEMENTAL RESISTANCE FOR SERIALLY IOUNTED LAllSk .Filed Nwe,i925 raienied Nov. 20,1928. UNITEDv STATES ALFRED LAMPE,OERERLIN-HALENSEE, GERMANY.

SUPPLEMENTAL RESISTANCE EoR SERIALLY-MOUNTED- LAMPS.

1,692,272 PATENT OFFICE.

Application `nled November 9, 1925, Serial No; 68,042and in GermanyvMay9, 1925,

the breakingof a lamp a supplemental re-.

sistance is switched into circuit in place of this particular lamp. Inthe well known arrangement of this kind which heretofore was regarded asthe'most simple, leastexpensive and space-saving device of the. kindreferred to a conductor of the so-called second class conductors,particularly carborundum, either as one solid piece .or as a powder, wasdisposed between tWo electrodes connected to 'the terminals of the lampand was employed as an automatically operating shunt-resistance. Thisarrangement, however, has not been universally accepted in practicaloperation, inasmuch as such -second class conduc-` tors are unsuitablefor the purposes indicated in vielw of the high specific resistancethereof, the slowness and imperfect operation produced when respondingto differences of voltage which become'evident only as a secondaryresult of t-he variation of their heated condition in acvcordance withthe passage of the current, and,particularly in view of the insufficientdegree of resistibility of such bodies. Now, in accordance with thisinvention,

the inconveniences above referred to in con- 40 nection withsupplemental resistances forserially arranged electric lamps and otherelectrically operated devices are eliminated by replacing thecarborundum referred to or.

other second class. conductors by metallic granules or metal chips whichare so disposed as to serve as a supplemental resistance which mayconsist of a great number of loosely-and adjacently disposed smallbodies arranged Vin shunt connection with relation to each particularlamp and adapted to bridge over the point of rupture produced by theinterruption of the circuit of the particular lamp. For this purposeironor a mixture of iron with another metal particularly nickel as an in- 56stance may be employed.

Upon the accompanying drawing I have loosely shown byway ofexemplification and in a somewhat diagrammatic manner an embodiment ofthe principles of this linvention insectional View, As appears from thedrawing, the insulating body L of a lamp socket vof ordinaryconstruction for incandescent ausser-:D

porcelain base k of the socket is provided with a transverse passage orcavity 'g into 'apertures of which provided on two sides of the socketsuitable extensions of the cur-A rent-admitting bars e and f are adaptedto project in such a manner as to provide sufiicient contact in allpositions of the'lamp socket lwith the mass of coarsely granular piecesof ironor of other metal filings or chips fully attaching the electrodese and y to the ends of the passage g they are not only tightly securedto the porcelain body of the socket vbut by this means they also providethe necessary closing of the passage g so as to keep the granules clcontained therein substantially adj acentl to each other. l

The mode of operation of the device described is substantially asfollows In the ordinary way of operation of the lamp or the like mountedin the socket described theY lamp will burn in vseries with a plurality(mostly seven or fifteen) of other similar lamps each of whichindividual lamps consumes only a fraction of the total voltage (forinstance lll volts). With a properly selected distance of the electrodese, f of the shunt resist-ance d its resistivity is infinitely large, aslong as a low partial voltage exists at the corresponding lampterminals. Hence the current owing through the shunt branch is equal tozero, so that the lamps arranged in serial connectionwill burn lwiththeir full illuminating strength and without any loss of current. Thisbehavior is due to the fact that veach individual particle of the greatnumberfof loosely arranged metal granules is surrounded by amicroscopically small insulating air or gas envelope. Now, -inasmuch asin view of the very high number of these 'small serially arranged sparkgaps only a very slight fraction of the lentire partial voltage of, forinstance 14 volts corresponds to each one of these gaps,the thusproduced searranged in the cavity g. By care,-

any unscrewinp4 i ot the series for instance 1G or 220 volt, .c iroduced at. the te ininals c and f of the socke` which line drop is as arule a multiple of `he partial Voltage correspondingl to one ot thelamps. illith a proper ad justnient of he several parts this increase otvoltage will cause ne limits ot `gap-breakiiw voltage bet-Ween tivoadjoiningy metal parts to be exceeded7 and by this means the numerousimnieasurably small spark ga 3s are broken through and the metal oartsare welded to each other at their points ot contact by the heat of thesmall umping` spark.

.By this metallic Welding` together or trittingA ot the loose metalparticles the entire mei tallic mass assumes the character of anordinary tirstfclass conductor and it nouY otters almost no furtherresistance of the passage ot the current. .,lVith the properdimensioninl:r ot the sectional area ot the resistor col- 3 umn thesupplemental resist-ance thus produced may be made equal to theresistance of the burning lamp. its long as no supplemental lamp hasbeen substituted tor t-he deitectiye or missing lamp, the supplementalresistance produced in the manner described remains in circuit andproduces the result that the entire `remaining series ot lamps continues to burn with the full illuminating strength. Any possibletendency likely to occur by Vibrations ot the loosely fritted granularmetallic mass an'd which may cause disaggregation of the granules isovercome by the tact 'that at the same moment the full voltage of theseries Will be created at the terminals e, j' with the result that the.aggro gates of granules will be tritted again.

As soon, however, as a supplemental lamp is substituted for the missinglamp a 'slight shaking of the socket is sutlicient to produce a completeuntritting of the conducting pasand to restore the ni.

ich becomes :aon-conducting condition9 *i i trie other lai hanging otthe decc thereore be eiiected wit-hou the switching out of the seriesthrough which the current is passed. v

` in yievvfot the sniallf amount ot' space required and the simplicity'ot construction. 'the supplemental resistance in accordance with theinvention may also be employed in oit `he series.

all other kinds of lamp sockets. and in the socket or in tlienjlass bodyot the incandescent lamp itselbetween the current admitting electrodeswhich is apoint ot import ance for the utilization and the inode otoperation ot the subject matter ot the invention. rlhc device may alsobe advantageously eluployed as an automatically operating supplementalresistance for other 'udsot electric lamps, thus for instance for arclanips` and i'or all kinds of serially connected electric pieces ofapparatus.

lt should be understood that the invention has only been describedherein in its broad features, Without being restricted to the particular description thereof, but uifulilications and changes may occurto suit local and other conditions and without..deviatingV 'troni thespirit and scope ot the invention as hereinsubstantially tubular cavityin said Socket,

a supply oi loosely*,aggregated small tragments ot metallic conductorsin said cavity, extensions at the non-contacting portions ot' saidterminals reaching into said cavity at opposite sides thereof .andclosing said cavity.

In testimony whereof l affix my signature.

ALFRED LAMPL.

ticeable the :fact that th Vfreshly su sti- 'cd burns Withthe lulllaminating

